Some Effects of a Topical Collagen-Based Matrix on the Microcirculation and Wound Healing in Patients With Chronic Venous Leg Ulcers: Preliminary Observations

A deeper look at low-frequency contact ultrasonic debridement in the clinical management of patients with diabetic foot ulcers

The current study aimed to evaluate the dispersal of solution and microbes (aerosol) in the clinical environment during treatment with Low-frequency contact ultrasonic debridement (LFCUD) with or without suction attachment in patients with diabetic foot ulcers (DFUs). We performed 20 treatments in 10 patients divided into two groups to receive the proposed LFCUD modalities. We measured the microbial load of the environment pre-treatment (sample M1), during treatment with each LFCUD modality (sample M2) and post-treatment (sample M3). The use of LFCUD debridement without a suction attachment results in significantly higher immediate contamination of the clinic environment than the suction attachment, particularly during the procedure (1.70 ± 0.98 log 10 CFU/mL versus 0.77 ± 0.85 log 10 CFU/mL, p = 0.035). When suction is not applied, there are statistically significant differences depending on whether the DFUs are neuropathic or neuroischemic, finding a greater number of microorganisms with high loads in neuropathic DFUs. We found a statistically significant positive correlation between wound area (r = 0.450, p = 0.047) and TBI (r = 0.651, p = 0.006) with the bacterial load during the LFCUD. Based on our results, we recommend using the personal protective equipment required to protect staff members and patients during treatment with LFCUD and using a suction attachment where clinically possible to reduce clinic environmental pollution, especially in neuropathic DFUs and those with larger areas.

Clinical and Histological Outcomes of Negatively Charged Polystyrene Microspheres Applied Daily Versus Three Times per Week in Hard-to-Heal Diabetic Foot Ulcers: A Randomized Blinded Controlled Trial

Negatively charged polystyrene microspheres (NCMs) have been demonstrated as a novel and effective therapy for managing hard-to-heal diabetic foot ulcers (DFUs). However, one limitation of this therapy is that the protocol is based on daily application, which sometimes does not fit local protocols of wound care. Thus, we aimed to analyze the safety and efficacy of a new dose regimen. We conducted a randomized blinded controlled trial in a specialized diabetic foot unit between May 2019 and February 2021 with a total of 30 patients who had neuropathic or neuroischemic DFUs that had not responded after four weeks of standard treatment. Patients were randomized consecutively into a group that received daily application (control) or one that received applications three times per week (experimental). The clinical outcomes were evaluated using the Wollina score and wound-area reduction (WAR) weekly during a treatment period of 28 days. The histological outcomes were assessed using a soft-tissue punch biopsy (3 mm) at 0, 14, and 28 days to evaluate cellular proliferation. The Wollina scores were higher at the end of treatment by week 4 in both groups, but the differences were not significant between groups. The averages were 6 (5, 7) points in Experimental group (EG) and 6 (6,7) points in Control group (CG) (p = 0.848). Wound area reduction at day 28 was 53.57 [37.43, 79.16] % in the CG and 79.37 [42.74, 93.57] % in the EG, without differences among groups (p = 0.305). Cellular proliferation was similar in both groups at day 28. Application three times per week showed similar clinical and histological outcomes to those of daily application, both dose regimens demonstrated significant improvement of granulation tissue formation and WAR during the treatment.

Antimicrobial effectiveness of wound matrices containing native extracellular matrix with polyhexamethylene biguanide

A variety of wound matrix materials that are designed to help heal both acute and chronic wounds are currently available. Because wounds often encounter opportunistic microbes that can delay healing, the effectiveness of these materials is often suboptimal, resulting in delayed or compromised wound healing. The importance of reducing and controlling wound microbes is well recognised and there are several antimicrobial options available to address this unmet clinical need. This study compares the antimicrobial and wound healing capabilities, both in vivo and in vitro against methicillin-resistant Staphylococcus aureus (MRSA) USA 300, for the following compounds: Collagen Wound Matrix-Anti Microbial (CWM-AM); Collagen Wound Matrix-Anti Microbial XT (CWM-AM XT); Antimicrobial Hydrofiber Wound Dressing (AHWD); Dermal Scaffold with Silver (DRSAg); Collagen Extracellular Matrix (CEM); Collagen Wound Matrix (CWM); Matrix Wound Dressing with Silver (MWDAg); Cadexomer Iodine Gel (CIG); Triple Antibiotic Ointment (TAO); and Antimicrobial Wound Gel (AWG). For the in vitro zone of inhibition assay, AWG and CIG had the largest diffused areas, followed by CWM-AM and CWM-AM XT. Furthermore, CWM-AM, CWM-AM XT, AWG, and CIG exhibited a persistent antimicrobial activity for up to 10 days after incubation. However, in the cytotoxicity studies performed using human fibroblasts, CWM-AM and CWM-AM XT had no detrimental effects in cell proliferation and viability, while AWG and CIG were cytotoxic and prohibitive for cell proliferation. Treatments were then assessed for microbiology and wound healing efficacy using an in vivo porcine deep reticular dermal wound model. CWM-AM XT displayed the greatest in vivo antimicrobial activity against MRSA USA300 and expedited the reepithelialisation at a faster rate than other treatment groups. This study shows that a novel collagen matrix containing an antimicrobial agent can reduce the bacterial load and support healing.

Use of oxidised regenerated cellulose/collagen dressings versus standard of care over multiple wound types: A systematic review and meta-analysis

Oxidised regenerated cellulose (ORC)/collagen dressings help maintain physiologically moist wound environments conducive to wound healing. While evidence supporting ORC/collagen dressing use exists, comprehensive assessment is needed. This systematic review/meta-analysis evaluated the performance of ORC/collagen dressings compared with standard dressings. A systematic literature search was performed using PUBMED, EMBASE, and QUOSA Virtual Library. Published studies and conference abstracts were assessed between 1 January 1996 and 27 July 2020. Comparative studies in English completed by 31 December 2019, with a study population ≥10 were included. Patient demographics, wound healing, and protease concentrations were extracted. A random-effect model was used to assess the effect of ORC/collagen dressings. Twenty studies were included following removal of duplicates and articles not meeting inclusion criteria. A statistically significant effect in favour of ORC/collagen dressings was found for wound closure (P = 0.027) and percent wound area reduction (P = 0.006). Inconclusive evidence or limited reporting prevented assessment of time to complete healing, days of therapy, number of dressing applications, pain, matrix metalloproteinase, elastase, plasmin, and gelatinase concentration. Statistically significant increase in wound closure rates and percent wound area reduction were observed in patients receiving ORC/collagen dressings compared with standard dressings in this systematic review/meta-analysis.

Ultrasonic-assisted wound debridement: report from a closed panel meeting

Mechanical debridement can be considered as an alternative to surgical debridement if surgery is not available, or is considered impractical or too high risk. One form of selective mechanical debridement is ultrasonic-assisted wound (UAW) debridement. As the published evidence on this is limited, a closed international expert meeting was held to review the existing evidence base on it, present preliminary findings of research currently in progress and discuss individual cases selected from the clinical experts' own practice. The panel also explored the potential barriers to the implementation of UAW debridement and how these might be addressed. It concluded there is sufficient evidence that UAW debridement is an effective method of cleansing and debriding almost all hard-to-heal wounds. Patients who are most likely to benefit from it are not medically stable, on anticoagulants, unable to visit a hospital for wound treatment, and/or have wounds with a poor vascular supply or are close to critical structures. The panel also observed that UAW debridement can be used to prepare the wound for negative pressure wound therapy (NPWT) or as an adjunctive to it. Given the potential to experience pain during the procedure, the panel considered that patients will benefit from topical analgesia. The panel noted that health professionals, patients and visitors must be protected from the aerosolisation associated with UAW, to reduce risk of cross-contamination.

Increasing Transcutaneous Oxygen Pressure in Patients With Neuroischemic Diabetic Foot Ulcers Treated With a Sucrose Octasulfate Dressing: A Pilot Study

Regarding the positive clinical outcomes of sucrose octasulfate impregnated dressing documented in neuroischemic diabetic foot ulcers (DFUs), we aimed to evaluate the microcirculatory status in patients with neuroischemic DFU through the use of sucrose octasulfate dressing. Eleven patients with neuroischemic DFU were included in a prospective pilot study between July 2019 and March 2020. We evaluated the effect in transcutaneous oxygen pressure (TcPO2; mm Hg) values within the use of a sucrose octasulfate dressing in the course of the healing process of neuroischemic DFUs (UrgoStart Contact, Laboratoires Urgo Medical). TcPO2 values were assessed at day 0 and monthly until wound healing was achieved. Additionally, wound healing process was evaluated using the Wollina score system and wound area surface, at day 0 and monthly until 20 weeks of follow-up or wound healing first occurred. TcPO2 values showed a significant increase between day 0 (29.45 ± 7.38 mm Hg) and wound closure (46.54 ± 11.45 mm Hg, P = .016), after dressing application. Wollina wound scores showed a significant improvement (4.2 ± 1.7 at day 0 to 5.4 ± 1.3 at the end of the study; P = .004). Median wound area at day 0 was 1.30 cm2, interquartile range [1.60-1] cm2, and 0.5 cm2 at week 4, interquartile range [1.1-0.1], P < .001. Median healing time was 8 weeks, interquartile range [8-5]. Treating a neuroischemic DFU with a sucrose octasulfate dressing in the standard of care showed an increase in skin oxygen pressure.

Combination therapy of oxidised regenerated cellulose/collagen/silver dressings with negative pressure wound therapy for coverage of exposed critical structures in complex lower-extremity wounds

Complex wounds with exposed critical structures such as tendon and bone are a conundrum in wound management, especially in the setting where the patient is not a suitable candidate for flap surgery. While the individual use of negative pressure wound therapy (NPWT) and oxidised regenerated cellulose (ORC)/collagen/silver (PROMOGRAN PRISMA) dressing has been described in the literature, there are little data on the efficacy of their combined use. In this study, we describe a novel technique of combining the use of NPWT and ORC/collagen/silver dressings to manage complex wound beds as an alternative management option for patients not suitable for reconstructive flap surgery. This technique was performed in a series of 37 patients with complex lower-extremity wounds that were not healing with conventional NPWT alone. All patients had open wounds with exposed critical structures that were difficult to manage, such as exposed tendon, bone, deep crevices, and joint. Successful coverage of exposed critical structures was achieved in 89% of patients, and coverage was achieved within 28 days of combination therapy in 82% of these patients, without any complications. The novel technique of combining ORC/collagen/silver dressing and NPWT provides a useful option in the armamentarium of a reconstructive surgeon dealing with difficult complex lower-extremity wounds.

Ultrasound-assisted debridement of neuroischaemic diabetic foot ulcers, clinical and microbiological effects: a case series

OBJECTIVE

To evaluate the clinical and microbiological effects of sequential wound debridement in a case series of neuroischaemic diabetic foot ulcers (DFUs) using an ultrasound-assisted wound debridement (UAW) device.

METHOD

A prospective, single-centre study, involving a case series of 24 neuroischaemic DFUs, was conducted to evaluate sequential wound debridement with UAW during a six-week treatment period. Soft tissue punch biopsies were taken every second week of treatment, both before and after wound debridement sessions. Qualitative and quantitative microbiological analysis was performed and wounds were assessed at patient admission, and before and after each debridement procedure.

RESULTS

Wound tissue quality scores improved significantly from a mean score of 2.1±1.3 points at patient inclusion, to 5.3±1.7 points (p=0.001). Mean wound sizes were 4.45cm² (range: 2-12.25cm²) at week zero, and 2.75cm² (range: 1.67-10.70cm²) at week six (p=0.04). The mean number of bacterial species per culture determined at week zero and at week six was 2.53±1.55 and 1.90±1.16, respectively (p=0.023). Wound debridement resulted in significant decreases in bacterial counts (1.17, 1.31 and 0.77 log units in colony forming units (CFU) for week zero, three and six, respectively). The average bacterial load in tissue samples before and after wound debridement after the six-week treatment was Log 5.55±0.91CFU/g and Log 4.59±0.89CFU/g, respectively (p<0.001).

CONCLUSIONS

The study results showed a significant bacterial load reduction in DFU tissue samples as a result of UAW debridement, independent of bacterial species, some of which exhibited antibiotic-resistance. Significant bacterial load reduction was correlated with improved wound conditions and significant reductions of wound size.

Clinical and Antimicrobial Efficacy of a Silver Foam Dressing With Silicone Adhesive in Diabetic Foot Ulcers With Mild Infection

The use of an antimicrobial dressing instead of a non-antimicrobial dressing may increase the number of diabetic foot ulcers healed over a medium-term follow-up period. The study aim was to evaluate the clinical and microbiological efficacy of a silver foam dressing in the management of diabetic foot ulcers. We conducted a single-center, prospective, open, noncontrolled study involving 21 outpatients with diabetic foot ulcers with mild infection. All patients received standard of care for their wounds and a silver foam dressing with silicone adhesive was applied twice per week for wound management during a 6-week treatment period. Soft tissue punch biopsies were taken every second week for qualitative and quantitative microbiological analysis. Wounds were assessed at patient admission, and wound bed tissue was evaluated for presence, quality, and consistency of granulation tissue. Clinical evaluation revealed improvements in wound conditions as a result of treatment with the silver dressing. Wollina wound scores improved significantly, from a mean score of 3.9 ± 1.6 points at inclusion to 6.1 ± 1.3 points at the end of the study (n = 19, P < .001). Treatment with the silver dressing resulted in significant decreases in the bioburden of classically considered diabetic foot ulcer pathogenic organisms such as Staphylococcus aureus, including methicillin-resistant Staphylococcus aureus, Enterobacteriaceae species, Pseudomonas aeruginosa, and other nonfermenting gram-negative bacilli. Findings revealed that the use of silver foam dressing significantly reduced the pathogenic bacterial load and markedly improved the clinical outcome in patients with diabetic foot ulcer with mild infection over a 6-week treatment period.

[Impact of various wound dressings on wound bed neoangiogenesis in patients with different forms of diabetic foot syndrome]

AIM

To investigate the impact of various wound dressings on wound bed neoangiogenesis in patients with different forms of diabetic foot syndrome (DFS).

SUBJECTS AND METHODS

The clinical (local tissue oxygenation) and immunohistochemical (CD31) markers of foot soft tissue neoangiogenesis were evaluated in patients with DFS receiving negative pressure (NP) therapy and collagen-containing dressings (CCDs) versus standard treatment. 63 patients with neuropathic and neuroischemic (without critical ischemia) forms of DFS were examined after wound debridement. In the postoperative period, 21 patients received NP treatment, CCDs were applied to 21 patients, and 21 patients had standard treatment.

RESULTS

During NP therapy, there was statistically significantly intensified local microhemodynamics, as evidenced by transcutaneous oximetry (p < 0.05); the remaining two groups showed no statistically significant differences in transcutaneous oxygen tension during the treatment. Immunohistochemical examination revealed a significant increase in the number of newly formed vessels, as shown by anti-CD31 antibody staining (p < 0.05), in patients who had NP therapy and CCDs (p < 0.05).

CONCLUSION

Vacuum (NP) therapy versus standard therapy most effectively affects wound bed neoangiogenesis. This is reflected in the increased local tissue microhemodynamics, as confirmed by immunohistochemical examination.

Oxidized Regenerated Cellulose/Collagen Dressings: Review of Evidence and Recommendations

OBJECTIVE

Healthcare systems are being challenged to manage increasing numbers of nonhealing wounds. Wound dressings are one of the first lines of defense in wound management, and numerous options exist. The oxidized regenerated cellulose (ORC)/collagen dressing may offer healthcare providers a robust and cost-effective tool for use in a variety of wounds.

DESIGN

A multidisciplinary panel meeting was convened to discuss the use of ORC/collagen dressings in wound care and provide practice recommendations. A literature search was conducted to provide a brief review of the peer-reviewed studies published between January 2000 and March 2016 to inform the meeting.

SETTING

A 2-day panel meeting convened in February 2017.

PARTICIPANTS

Healthcare providers with experience using ORC/collagen dressings. This multidisciplinary panel of 15 experts in wound healing included podiatrists, wound care specialists (doctors, certified wound care nurses, and research scientists), and an orthopedist.

RESULTS

The literature search identified 58 articles, a majority of which were low levels of evidence (69.3% were level 3 or lower). Panel members identified wound types, such as abrasions, burns, stalled wounds, diabetic foot ulcers, and pressure injuries, where ORC/collagen dressing use could be beneficial. Panel members then provided recommendations and technical pearls for the use of ORC/collagen dressings in practice. Barriers to ORC/collagen dressing use were discussed, and potential resolutions were offered.

CONCLUSIONS

An ORC/collagen dressing can be a critical tool for clinicians to help manage a variety of wounds. Clinical and economic studies comparing standard-of-care dressings and plain collagen dressings to ORC/collagen dressings are needed.

Protease-modulating matrix treatments for healing venous leg ulcers

BACKGROUND

Venous leg ulcers (VLUs) are open skin wounds on the lower leg that occur because of poor blood flow in the veins of the leg; leg ulcers can last from weeks to years, and are both painful and costly. Prevalence in the UK is about 2.9 cases per 10,000 people. First-line treatment for VLUs is compression therapy, but around 60% of people have unhealed ulcers after 12 weeks' treatment and about 40% after 24 weeks; therefore, there is scope for further improvement. Limited evidence suggests non-healing leg ulcers may have persisting elevated levels of proteases, which is thought to deter the later stages of healing; thus, timely protease-modulating matrix (PMM) treatments may improve healing by physically removing proteases from the wound fluid.

OBJECTIVES

To determine the effects of protease-modulating matrix (PMM) treatments on the healing of venous leg ulcers, in people managed in any care setting.

SEARCH METHODS

In September 2016 we searched: the Cochrane Wounds Specialised Register; CENTRAL; Ovid MEDLINE; Ovid MEDLINE (In-Process & Other Non-Indexed Citations); Ovid Embase and EBSCO CINAHL Plus. We also searched clinical trials registries for ongoing and unpublished studies, and scanned reference lists of relevant included studies as well as reviews, meta-analyses and health technology reports to identify additional studies. There were no restrictions with respect to language, date of publication or study setting.

SELECTION CRITERIA

We searched for published or unpublished randomised controlled trials (RCTs) that evaluated PMM treatments for VLUs. We defined PMM treatments as those with a purposeful intent of reducing proteases. Wound healing was the primary endpoint.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed study selection, risk of bias assessment and data extraction.

MAIN RESULTS

We included 12 studies (784 participants) in this review; sample sizes ranged from 10 to 187 participants (median 56.5). One study had three arms that were all relevant to this review and all the other studies had two arms. One study was a within-participant comparison. All studies were industry funded. Two studies provided unpublished data for healing.Nine of the included studies compared PMM treatments with other treatments and reported results for the primary outcomes. All treatments were dressings. All studies also gave the participants compression bandaging. Seven of these studies were in participants described as having 'non-responsive' or 'hard-to-heal' ulcers. Results, reported at short, medium and long durations and as time-to-event data, are summarised for the comparison of any dressing regimen incorporating PMM versus any other dressing regimen. The majority of the evidence was of low or very low certainty, and was mainly downgraded for risk of bias and imprecision.It is uncertain whether PMM dressing regimens heal VLUs quicker than non-PMM dressing regimens (low-certainty evidence from 1 trial with 100 participants) (HR 1.21, 95% CI 0.74 to 1.97).In the short term (four to eight weeks) it is unclear whether there is a difference between PMM dressing regimens and non-PMM dressing regimens in the probability of healing (very low-certainty evidence, 2 trials involving 207 participants).In the medium term (12 weeks), it is unclear whether PMM dressing regimens increase the probability of healing compared with non-PMM dressing regimens (low-certainty evidence from 4 trials with 192 participants) (RR 1.28, 95% CI 0.95 to 1.71). Over the longer term (6 months), it is also unclear whether there is a difference between PMM dressing regimens and non-PMM dressing regimens in the probability of healing (low certainty evidence, 1 trial, 100 participants) (RR 1.06, 95% CI 0.80 to 1.41).It is uncertain whether there is a difference in adverse events between PMM dressing regimens and non-PMM dressing regimens (low-certainty evidence from 5 trials, 363 participants) (RR 1.03, 95% CI 0.75 to 1.42). It is also unclear whether resource use is lower for PMM dressing regimens (low-certainty evidence, 1 trial involving 73 participants), or whether mean total costs in a German healthcare setting are different (low-certainty evidence, 1 trial in 187 participants). One cost-effectiveness analysis was not included because effectiveness was not based on complete healing.

AUTHORS' CONCLUSIONS

The evidence is generally of low certainty, particularly because of risk of bias and imprecision of effects. Within these limitations, we are unclear whether PMM dressing regimens influence venous ulcer healing relative to dressing regimens without PMM activity. It is also unclear whether there is a difference in rates of adverse events between PMM and non-PMM treatments. It is uncertain whether either resource use (products and staff time) or total costs associated with PMM dressing regimens are different from those for non-PMM dressing regimens. More research is needed to clarify the impact of PMM treatments on venous ulcer healing.

Leg ulcer treatment outcomes with new ovine collagen extracellular matrix dressing: a retrospective case series

The purpose of this study was to describe the rate of closure observed in venous leg ulcers during treatment with ovine collagen extracellular matrix dressings and compression. Fourteen patients with 23 wounds were retrospectively evaluated with respect to healing rates, time to closure, and weekly facility charge fees.

Purified type I collagen wound matrix improves chronic wound healing in patients with recessive dystrophic epidermolysis bullosa

Recessive dystrophic epidermolysis bullosa is a severe genetic blistering skin condition resulting in chronic wounds. Nonhealing wounds were treated over 8 weeks using a reconstituted natural purified type I collagen skin substitute. Chronic wounds were defined as nonhealing wounds present for longer than 6 months. For each patient, two chronic wounds were identified and randomized into a control or treatment group. Both groups received standard-of-care wound dressings. The treatment group received an additional type I collagen skin substitute. Wound size was measured at baseline and weeks 1, 4, and 8. Pain, pruritus, and burning and stinging were assessed. Wound cultures were obtained at baseline and thereafter as was considered clinically relevant. Ten subjects were enrolled; seven completed the study. Six subjects showed a positive response to the type I collagen skin substitute. Three subjects demonstrated full wound reepithelialization. Wounds treated using the collagen skin substitute showed statistically significantly greater improvement. Average scores for pruritus and pain decreased significantly. Reconstituted natural purified type I collagen skin substitutes improved the healing of chronic wounds and may be a valuable addition to the epidermolysis bullosa wound care arsenal.

Noninvasive imaging technologies for cutaneous wound assessment: A review

The ability to phenotype wounds for the purposes of assessing severity, healing potential and treatment is an important function of evidence-based medicine. A variety of optical technologies are currently in development for noninvasive wound assessment. To varying extents, these optical technologies have the potential to supplement traditional clinical wound evaluation and research, by providing detailed information regarding skin components imperceptible to visual inspection. These assessments are achieved through quantitative optical analysis of tissue characteristics including blood flow, collagen remodeling, hemoglobin content, inflammation, temperature, vascular structure, and water content. Technologies that have, to this date, been applied to wound assessment include: near infrared imaging, thermal imaging, optical coherence tomography, orthogonal polarization spectral imaging, fluorescence imaging, laser Doppler imaging, microscopy, spatial frequency domain imaging, photoacoustic detection, and spectral/hyperspectral imaging. We present a review of the technologies in use or development for these purposes with three aims: (1) providing basic explanations of imaging technology concepts, (2) reviewing the wound imaging literature, and (3) providing insight into areas for further application and exploration. Noninvasive imaging is a promising advancement in wound assessment and all technologies require further validation.

Effectiveness of an acellular synthetic matrix in the treatment of hard-to-heal leg ulcers

Hard-to-heal leg ulcers are a major cause of morbidity in the elderly population. Despite improvements in wound care, some wounds will not heal and they present a significant challenge for patients and health care providers. A multi-centre cohort study was conducted to evaluate the effectiveness and safety of a synthetic, extracellular matrix protein as an adjunct to standard care in the treatment of hard-to-heal venous or mixed leg ulcers. Primary effectiveness criteria were (i) reduction in wound size evaluated by percentage change in wound area and (ii) healing assessed by number of patients healed by end of the 12 week study. Pain reduction was assessed as a secondary effectiveness criteria using VAS. A total of 45 patients completed the study and no difference was observed between cohorts for treatment frequency. Healing was achieved in 35·6% and wound size decreased in 93·3% of patients. Median wound area percentage reduction was 70·8%. Over 50% of patients reported pain on first visit and 87·0% of these reported no pain at the end of the study. Median time to first reporting of no pain was 14 days after treatment initiation. The authors consider the extracellular synthetic matrix protein an effective and safe adjunct to standard care in the treatment of hard-to-heal leg ulcers.

Healing process of venous ulcers: the role of microcirculation

In order to describe adequately the process of healing in the intermediate degrees, we investigated microcirculatory changes in the venous ulcers at well-defined stages of wound repair. We investigated dynamic changes in microcirculation during the healing process of venous ulcers. Ten venous ulcers were investigated in three consecutive clinical stages of wound healing: non granulation tissue (NGTA), GTA and scar. Subpapillary microcirculation was measured by laser Doppler perfusion (LDP) imaging and expressed using LDP values in arbitrary units. Nutritive perfusion by capillary microscopy and expressed as capillary density (CD) - the number of capillaries per square millimetre. Before the development of GTA the LDP was low (median 1·35; lower-upper quartiles 0·71-1·83) accompanied with zero CD in all but one patient who had a density of 1. With the first appearance of GTA in the same area, the LDP was improved (2·22; 1·12-2·33; P = 0·0024) when compared with NGTA, in combination with a significant increase in CD (1·75; 0-3; P = 0·0054). In scar, the LDP was similar to that in the NGTA (1·03; 0·77-1·83; P = 0·278), combined with the highest CD (5·75; 4·5-8) in comparison with the previous stages of the area (for both pairs, P < 0·0001). Venous ulcers are caused by poor nutritive and subpapillary perfusion. Subpapillary perfusion plays a major role in the formation of GTA. In a scar, the increased nutritive perfusion is sufficient to cover the blood supply and keep skin viable while subpapillary perfusion is low.

Special considerations in wound bed preparation 2011: an update©

This article builds and expands upon the concept of wound bed preparation introduced by Sibbald et al in 2000 as a holistic approach to wound diagnosis and treatment of the cause and patient-centered concerns such as pain management, optimizing the components of local wound care: Debridement, Infection and persistent Inflammation, along with Moisture balance before Edge effect for healable but stalled chronic wounds.

Clinical experiences derived from implementation of an easy to use concept for treatment of wound healing by secondary intention and guidance in selection of appropriate dressings

The main objective of this case-cohort-type observational study conducted at different Surgical Departments of the Charité-Universitätsmedizin in Berlin was to evaluate the sequential use concept first described by Systagenix Wound Management in 2007. Fifty-two patients with different wound healing by secondary intention were treated for 7 weeks at the Charité-Universitätsmedizin in Berlin. A multidisciplinary team worked together to reach consensus in wound assessment; in classification of infection status according to the criteria described by European Wound Management Association (EWMA); in treatment protocol and on dressings to be used to 'cover' wounds. Before dressing application, all wounds were cleaned from debris. Following the sequential use concept, wounds classified as stages 2 and 3 were dressed with SILVERCEL(®) and TIELLE(®) or TIELLE PLUS(®) to 'clean' the wounds. After 2-3 weeks, treatment was changed to PROMOGRAN PRISMA(®) and TIELLE(®) to 'close and cover' wounds, thus providing optimal wound healing. Wounds classified as non infected were dressed with PROMOGRAN PRISMA(®) and TIELLE(®) during the complete treatment period. Patients were asked to evaluate the treatment using a simplified questionnaire developed at the Charité-Universitätsmedizin in Berlin. Wounds comprised 37 surgical procedures, 8 chronic mixed ulcer, 4 pressure sores, 1 diabetic foot ulcer, 1 venous leg ulcer, and 1 mixed arterial/venous ulcer. At baseline, 12 wounds were classified as stage 3, 38 wounds as stage 2 and 2 wounds as stage 1. After 7 weeks of treatment, all patients showed a positive clinical response to the sequential use treatment. Results of wound size showed a high significant progression of wound healing expressed with a profound reduction of wound area (P in all measurements <0·001, chi-square test) and improved granulation. This study summarises the clinical experiences derived from the evaluation of the sequential use concept in the daily clinical practice of wound treatment. On the basis of the wound healing results, patients' evaluation of treatment and the clinicians' and staff experiences, this concept was implemented at different Surgical Departments of the Charité-Universitätsmedizin in Berlin.

Synergistic action of protease-modulating matrix and autologous growth factors in healing of diabetic foot ulcers. A prospective randomized trial

This study tests the hypothesis that addition of a protease-modulating matrix enhances the efficacy of autologous growth factors in diabetic ulcers. Fifty-one patients with chronic diabetic foot ulcers were managed as outpatients at the Democritus University Hospital of Alexandroupolis and followed up for 8 weeks. All target ulcers were > or = 2.5 cm in any one dimension and had been previously treated only with moist gauze. Patients were randomly allocated in three groups of 17 patients each: Group A was treated only with the oxidized regenerated cellulose/collagen biomaterial (Promogran, Johnson & Johnson, New Brunswick, NJ), Group B was treated only with autologous growth factors delivered by Gravitational Platelet Separation System (GPS, Biomet), and Group C was managed by a combination of both. All ulcers were digitally photographed at initiation of the study and then at change of dressings once weekly. Computerized planimetry (Texas Health Science Center ImageTool, Version 3.0) was used to assess ulcer dimensions that were analyzed for homogeneity and significance using the Statistical Package for Social Sciences, Version 13.0. Post hoc analysis revealed that there was significantly greater reduction of all three dimensions of the ulcers in Group C compared to Groups A and B (all P<.001). Although reduction of ulcer dimensions was greater in Group A than in Group B, these differences did not reach statistical significance. It is concluded that protease-modulating dressings act synergistically with autologous growth factors and enhance their efficacy in diabetic foot ulcers.

The extracellular matrix in wound healing: a closer look at therapeutics for chronic wounds

Disappointing results with the use of exogenous recombinant growth factors in chronic wounds have redirected the focus to the extracellular matrix (ECM). Newer research has clearly changed our view on the role of the ECM in tissue repair and dismissed the dogma that the sole function of ECM is a passive physical support for cells. It is now clear that intact or fragmented ECM molecules are capable of transducing signals pivotal for cell processes in wound healing primarily via integrin interactions in concert with growth factor activation. In addition, our knowledge about ECM molecules in minute concentrations with biological activity, but devoid of significant structural influence, is increasing. This article reviews the multifaceted molecular roles of ECM in the normal wound-healing process and some molecular abnormalities in chronic wounds, and touches on potential therapies based on the developments of tissue biology.